The
visual system processes patterns of light and converts them into
useful information. Specialized neurons in the retina respond to
specific excitation patterns. Some respond to motion speed, others
to motion direction. Others are edge detectors that differentially
respond only to very precisely oriented edges. Still others fire
continuously--except when stimulated by a particular pattern.

Messages
from these cells are transmitted to the brain through two massively
parallel processing systems. As
this information is received in the visual cortex, it is further
analyzed and interpreted in terms of contrast, linear pattern, and
image movement. This analysis occurs in a set sequence from cell-to-cell
with each cell responsible for analyzing a specific detail within
the image pattern.

The
brain attempts to make sense of the information received by referencing
our prior learning and experience with pattern perception and recognition.
The human visual system is an extremely powerful parallel processor
and highly complex pattern analyzer. It is closely tied to areas
of the brain responsible for recognition, understanding, and recall.
Vision is superior to any other sense for certain information conveyance.